At the National Theatre in London, the play Our Class is pulling in crowds. It examines the massacre by a small group of antisemitic Poles of hundreds of Jews in Jedwabne in north east Poland in 1941. No Nazis were involved. The massacre was covered up by the communist rulers in Poland after 1945. Not until well after the end of communism did the facts come to light. The inconvenient truth that some Poles had taken part in a massacre of Jews caused fury in the rightwing circles in Poland associated with Radio Maryja, the anti-Jewish radio station and among many Polish politicians who felt their nation's honour had been besmirched.

In 2001, Poland's president, Aleksander Kwasniewski, went to Jedwabne to apologise. Like Willy Brandt kneeling at the Warsaw Ghetto in 1970, Kwasniewski felt atonement was needed. As Anita Prazmowska has related here, his gesture was criticised by many rightwing Poles, including the rising star of Polish Catholic nationalist politics, Michal Kaminski. His language was lurid and vivid. It upset many Jews. He tried to backtrack but his remarks had been taped.

Mr President should not take the guilt on the Polish nation, the whole nation that he should represent for what happened in Jedwabne and apologise in its name. I am ready to say the word: I am sorry but under two conditions. First of all, I need to know what I am apologising for. I apologise for a handful of outcasts. Secondly, I can do that if I know that someone from the Jewish side will apologise for what the Jews did during the Soviet occupation between 1939 and 1941. For the mass collaboration of the Jewish people with the Soviet occupier, for fighting Polish partisans in this area. And eventually, for murdering Poles.

Michal Kaminski has now come to prominence after David Cameron ordered Tory MEPs to serve under his leadership in the European parliament, as part of the Conservative policy of breaking links with mainstream centre-right parties in Europe.

I do not believe that Kaminski is a dedicated antisemite, any more than I believe Ken Livingstone is – despite the grave upset the former mayor of London caused with his offensive remarks to a Jewish journalist or his outspoken attacks on Israel. But if politicians of the left are to face examination of their statements on Jewish questions, then politicians of the right also have to face scrutiny. Michael Schudrich, Poland's Chief Rabbi, got it right when he issued this carefully worded statement about Kaminski when journalists started investigating the Polish MEP's alliance with the Conservative party:

I do not comment on political decisions. However, it is clear that Mr Kaminski was a member of NOP, a group that is openly far right and neo-nazi. Anyone who would want to align himself with a person who was an active member of NOP and the Committee to Defend the Good Name of Jedwabne (which was established to deny historical facts of the massacre at Jedwabne) needs to understand with what and by whom he is being represented.

Stephen Pollard, the editor of the Jewish Chronicle, takes a different line. In a harsh personal attack on the foreign secretary, David Miliband, Pollard accuses him of being "disgraceful" and "shameful" because at the Labour party conference he mentioned the background of the Conservatives' new ECR partners from Latvia and Poland.

I have spoken to many Poles – journalists, ambassadors and politicians – about Michal Kaminski. He is described as someone who shoots his mouth off without thinking. He not a roaring antisemite, but his intervention over Jedwabne troubled many. Pollard proclaims Kaminski a hero of the anticommunist struggle. But every young Pole in that era was anticommunist. Most supported the underground Solidarity trade union. Only a fringe minority like Kaminski signed up to a party which was linked to the darkest days of Polish antisemitism and affiliated to the neo-fascist European National Front.

Conservative press officers have been briefing heavily in an effort to clean up Kaminski's British image. A decent Tory MEP, Timothy Kirkhope, was wheeled out to justify the expulsion of the true blue Yorkshire Conservative MEP, Edward McMillan-Scott, after that latter protested about the rise of "respectable fascism" in the European parliament. Kirkhope wrote an article in the Yorkshire Post, which uses strikingly similar language and arguments to Pollard.

My perspective on this derives from the fact that I chaired an all-party commission of inquiry into antisemitism, and I appreciate the support David Cameron and Tory MPs give to the common fight against antisemitism, as well their support for the Jewish community in Britain. I also chair the European Institute for the Study of Contemporary Antisemitism. The accusation of antisemitism is too easily sprayed about. But I have no doubt that antisemitism in east European politics remains a major problem.

I find it disturbing, then, that the editor of the Jewish Chronicle does not share the concerns of many about Kaminski, who is due to speak at the Conservative party conference. I am disappointed also that the Board of Deputies of British Jews has claimed to find nothing "objectionable" or "sinister" in Kaminski's previous remarks; this seems complacently incurious.

I hope that Kaminski uses the opportunity of addressing the Conservative conference to distance himself from Radio Maryja and make clear that the racism and homophobia should have no place in European politics.